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Montana

Analysis of the Mountain Plover Mating System Using Microsatellite Analysis

Code:

RB00CNJ.8

A Mountain plover. Photo by Marcus Martin.

Abstract:

Mountain Plovers have an uncommon parental-care system where males and females tend separate nests. In Montana, males arrive at breeding grounds first, set up territories, and display to attract a female. After mating and laying an initial set of eggs, a female mates with other males, providing eggs for them to incubate. Courtship activity between multiple males and females within a single breeding season has been documented several times but few copulations have been observed. In this study we are examining the prevalence of multiple paternity within male- and female-tended broods using DNA extracted from chicks and the tending adult. This research is in collaboration with Iowa State University.

Examining Range-wide Connectivity in White-tailed Ptarmigan

Code:

RB00CNJ.26.3

A White-tailed Ptarmigan on Mt. Evans in Colorado. Photo by Cameron Aldridge, USGS.

Abstract:

The goal of this study is to document levels of connectivity among white-tailed ptarmigan populations. Our preliminary results, based on microsatellite loci, revealed that there is significant population genetic structure throughout the species’ range. The Colorado and Vancouver Island populations were the most isolated and there was limited connectivity among populations in Alaska, the Yukon, Washington, and Montana. There is little evidence for movement from Colorado northward or from Vancouver Island eastward, raising concerns for the long term viability of two subspecies. As these areas are most impacted by climate change, this lack of connectivity to the core part of the range may have implications for the species’ ability to track shifting habitats due to warming climates.

Examining Current Subspecies Delineations in White-tailed Ptarmigan Using Genomic Data

The delineation of populations that are evolutionarily and demographically distinct is an important step in the development of species-specific management plans. Such knowledge is necessary for learning how conservation threats vary across a species’ range, for devising strategies to increase population growth rates, and for providing legal protection at the intraspecific level. It is also essential for conserving long-term evolutionary resilience, given that the genetic diversity that has evolved in response to spatial variation in environmental conditions could provide the raw ingredients necessary to fuel future adaptive evolution. We are using genomic data to delineate distinct evolutionary units across the range of the white-tailed ptarmigan. This information will inform management strategies for this alpine species, which may be vulnerable to climate change.

The Greater Sage-Grouse, has been observed, hunted, and counted for decades. The sagebrush biome, home to the Greater Sage-Grouse, includes sagebrush-steppe and Great Basin sagebrush communities, interspersed with grasslands, salt flats, badlands, mountain ranges, springs, intermittent creeks and washes, and major river systems, and is one of the most widespread and enigmatic components of Western U.S. landscapes. Over time, habitat conversion, degradation, and fragmentation have accumulated across the entire range such that local conditions as well as habitat distributions at local and regional scales are negatively affecting the long-term persistence of this species. Historic patterns of human use and settlement of the sagebrush ecosystem have contributed to the current condition and status of sage-grouse populations. The accumulation of habitat loss, persistent habitat degradation, and fragmentation by industry and urban infrastructure, as indicated by U.S. Fish and Wildlife Service (USFWS) findings, presents a significant challenge for conservation of this species and sustainable management of the sagebrush ecosystem. Because of the wide variations in natural and human history across these landscapes, no single prescription for management of sagebrush ecosystems (including sage-grouse habitats) will suffice to guide the collective efforts of public and private entities to conserve the species and its habitat.

This report documents and summarizes several decades of work on sage-grouse populations, sagebrush as habitat, and sagebrush community and ecosystem functions based on the recent assessment and findings of the USFWS under consideration of the Endangered Species Act. As reflected here, some of these topics receive a greater depth of discussion because of the perceived importance of the issue for sagebrush ecosystems and sage-grouse populations. Drawing connections between the direct effects on sagebrush ecosystems and the effect of ecosystem condition on habitat condition, and finally the connection between habitat quality and sage-grouse population dynamics remains an important goal for science, management, and conservation. This effort is necessary, despite the perception that these complicated, indirect relations are difficult to characterize and manage, and the many advances in understanding and application developed toward this end have been documented here to help inform regional planning and policy decisions.

Publication Title:

Contraception can lead to trophic asynchrony between birth pulse and resources

Abiotic inputs such as photoperiod and temperature can regulate reproductive cyclicity in many species. When humans perturb this process by intervening in reproductive cycles, the ecological consequences may be profound. Trophic mismatches between birth pulse and resources in wildlife species may cascade toward decreased survival and threaten the viability of small populations. We followed feral horses (Equus caballus) in three populations for a longitudinal study of the transient immunocontraceptive porcine zonapellucida (PZP), and found that repeated vaccinations extended the duration of infertility far beyond the targeted period. After the targeted years of infertility, the probability of parturition from post-treated females was 25.6% compared to 64.1% for untreated females, when the data were constrained only to females that had demonstrated fertility prior to the study. Estimated time to parturition increased 411.3 days per year of consecutive historical treatment. Births from untreated females in these temperate latitude populations were observed to peak in the middle of May, indicating peak conception occurred around the previous summer solstice. When the post-treated females did conceive and give birth, parturition was an estimated 31.5 days later than births from untreated females, resulting in asynchrony with peak for age availability. The latest neonate born to a post-treated female arrived 7.5 months after the peak in births from untreated females, indicating conception occurred within 24–31 days of the winter solstice. These results demonstrate surprising physiological plasticity for temperate latitude horses, and indicate that while photoperiod and temperature are powerful inputs driving the biological rhythms of conception and birth in horses, these inputs may not limit their ability to conceive under perturbed conditions. The protracted infertility observed in PZP-treated horses may be of benefit for managing over abundant wildlife, but also suggests caution for use in small refugia or rare species.